search for magnetic refrigerant materials
DESCRIPTION
Search for magnetic refrigerant materials. - Lian Zhang. WZI group meeting May 28 th 2003, UvA. Outline. What & why is MR? Search for candidate materials Gd 5 (Si,Ge) 4 Fe 2 Mn(Si,Ge) La(Fe,Si) 13 MnFe(P,As) Conclusion. Fleet. FR de Boer, KHJ Buschow - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/1.jpg)
- Lian Zhang
Search for magnetic refrigerant materials
WZI group meeting May 28WZI group meeting May 28thth 2003, UvA 2003, UvA
![Page 2: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/2.jpg)
Outline
What & why is MR? Search for candidate materials
Gd5(Si,Ge)4
Fe2Mn(Si,Ge)
La(Fe,Si)13
MnFe(P,As) Conclusion
![Page 3: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/3.jpg)
Fleet
FR de Boer, KHJ Buschow
E Brück, A de Visser, J Klaasse, YK Huang
O Tegus
AL Wolf
![Page 4: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/4.jpg)
Why magnetic refrigeration? Conventional gas expansion cooling
Ozone depletion Global warming
Green MR Higher efficiency Less noisy More compact Low temperature capability
![Page 5: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/5.jpg)
Magnetic Refrigeration• Magnetic-materials change in temperature if subjected to
magnetic-field change Magnetocaloric effect
)()(),(),( TSTSTBSTBS ellatmag
S
T
B0
B=0
Ericsson
Q
Q
Carnot
![Page 6: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/6.jpg)
T1T2
S2
S1
Sm
Tad
Refrigerant capacity
Table-like
S
T
Integration from isothermal magnetization curves
Directly measure or compute from specific heat measurements
![Page 7: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/7.jpg)
T
SB
M B1 > B2
T1
T2
T3
T4
:
:
Tn
Composite materialTC
Field-induced or not, Field-induced or not, behaves differently. behaves differently.
![Page 8: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/8.jpg)
GdGd55(Si,Ge)(Si,Ge)44
Magnetostructural Magnetostructural transitiontransition
MM
TT
Hysteresis
Misleading messageMisleading message
![Page 9: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/9.jpg)
M. Nazih Solid State Comunications 126 (2003)
210 220 230 240 250 260 270 280 290 300 310
0
10
20
30
40
50
Gd5Si
1.7Ge
2.3 Sigle Crystal //a
1T 2T 3T 4T 5T
T (K)
-S
(J/
kgK
)
O. Tegus Physica B 319 (2002)
![Page 10: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/10.jpg)
Fe2Mn(Si1-xGex)
Fe3Si: TC > 800 K
Fe2MnSi: TC ~ 250 K
Cubic D03
Heusler-type
Fe3Ge: D019 (HT)
L12 (LT)
![Page 11: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/11.jpg)
20 30 40 50 60 70 80
Inte
nsity
(ar
b. u
nit)
10 h
4 h
2 h
1 h
0.5 h GeFeGeMn
Ge
Fe (100)
Mn
Ge (111)
2 (Deg)
L. Zhang J. Alloys Comp. 352 (2003)
D03 D019
![Page 12: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/12.jpg)
0.0 0.2 0.4 0.6 0.8 1.00
100
200
300
400
500
D019
D03
Para
T (
K)
x
0.0 0.2 0.4 0.6 0.8 1.0
5.66
5.68
5.70
5.72
5.74
5.76
5.78
a
(Å
)
X (Ge content)
Lattice change with Ge content
TC - Ge content
![Page 13: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/13.jpg)
20 30 40 50 60 70 80 90 100
D019
D019
+D03
D03
Fe2MnSi
1-xGe
x
x=1
x=0.8
x=0.6
x=0.5
x=0.4
x=0.2
x=0
In
ten
sit
y (
arb
. u
nit
)
2 (Deg)
30 40 50 60 70 80 90 100
440
422
400
220
00440
1222
203
220
202
201
002
200
Difference
Calculated
Observed
Inte
nsity
(ar
b. u
nit)
2 (Deg)
L. Zhang Physica B 328 (2003)
![Page 14: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/14.jpg)
0 50 100 150 200 250 300 350 4000.0
0.2
0.4
0.6
0.8
1.0
1.2
a
M
( B
/f.u
.)
T (K)
0 50 100 150 200 250 300 350 4000.0
0.5
1.0
1.5
2.0
2.5
3.0
b
M ( B
/f.u
.)
T (K)
220 240 260 280 3000.0
0.5
1.0
1.5
B=2T
B=5T
-S
(J/
kg·K
)
T (K)
Disappointed!
![Page 15: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/15.jpg)
La(Fe,Si)13
The highest 3d metal concentration (1:13) in RT intermetallic compounds
Failed to be a good permanent magnet
Cubic: weak anisotropy
Palstra 1983
![Page 16: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/16.jpg)
FeI @8b
FeII @96i
La @8a
Hypothetical LaFe13 structure:
Space group = Fm-3c
Unit cell = 8 f.u. = 112 atoms
= 8 La + 8 FeI + 96 FeII
Al, Si
Moze 1999
![Page 17: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/17.jpg)
Modification
Substitution of Fe by other transition metalsMn: failed to get single phase LaFe10.92Mn0.65Si1.43 Co: LaFe10.92Co0.65Si1.43 has a 2nd transition at TC=265K
Doping with interstitial atomsB: -Fe emerges in small amount of doping (B=0.2)N: difficulty in diffusion makes sample inhomogeneous
and broadens the transition enormously
C: saturated at C=0.5, while TC=250K
![Page 18: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/18.jpg)
![Page 19: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/19.jpg)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.00.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
B/F
e
B (T)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.00.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
B/F
e
B (T)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.00.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
B/F
e
B (T)
Field step 0.1T
Field step 0.02T
Field step 0.005T
Be cautious with the height of S peak when it is a 1st order field-induced transition.
![Page 20: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/20.jpg)
186 188 190 192 194 196
-40
-20
0
20
40
60
-
S
T (K)
For the field-induced 1st order transition, the field-up S-T show point rotation symmetry with the field-down S-T curve.
![Page 21: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/21.jpg)
MnFe(P,As)
![Page 22: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/22.jpg)
MnFePMnFeP MnFeAsMnFeAs
TT(K)(K)
400
300
200
100OrthOrth
AFAF
TTNN
TTNN
AFAF
TTCC
FF
TetrTetrHexHex
TTNN
ss
((BB/f.u.)/f.u.)ss
4
3
2
1
AFAF
Beckman-Lundgren, 1991Beckman-Lundgren, 1991
![Page 23: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/23.jpg)
O. Tegus Physica B 319 (2002)
![Page 24: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/24.jpg)
Virgin effectVirgin effect
![Page 25: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/25.jpg)
44 46 48 50 52 54 56
In
tens
ity
2deg.)
c
b
a
a
b
c
![Page 26: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/26.jpg)
X=0.4X=0.4 X=0.2X=0.2
![Page 27: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/27.jpg)
X=0.2
X=0.2
X=0.4
![Page 28: Search for magnetic refrigerant materials](https://reader035.vdocuments.net/reader035/viewer/2022062309/56814979550346895db6c4a9/html5/thumbnails/28.jpg)
Conclusion
Materials for MR are ready Much room for improvement Behaviors vary: rich ingredients Theories are called Accommodate engineering challenges